In 2015, this match-up was the Gold Cup final. That was unexpected, but not nearly as unexpected as it would be in 2017.
For a start, the knockout round draw makes it unlikely (it's possible that that third-placed team from Group C meets the group winner or runner-up in the final, but not particularly probable). More pertinently, both Jamaica and Mexico sent strong sides out to the last Gold Cup. This time around, both are fielding B-teams, for different reasons.
In El Tri's case, the A-team played Confederations Cup this summer, so Gold Cup is a chance for second-tier players to stake a claim to roles in the World Cup qualifiers ahead. Even Mexico's B-team will be regarded as having under-performed if it doesn't make the final, but if it is going to slip up, it is expected that slip will come in the knockout rounds.
Mexico has already beaten El Salvador relatively comfortably in this group stage, and is expected to make similarly light work of what looks a lightweight Jamaica side.
The Reggae Boyz have longer-term goals in mind for the squad at this Gold Cup. The 2018 World Cup is already out of reach and the selectors have been focused on Jamaica-born players - many playing in Jamaica - who might benefit from exposure to higher-profile, higher-level international matches.
Not all of the players in the current squad are likely to be able to contribute to the team's effort to qualify for the 2022 World Cup, but what Jamaica is looking for is to develop a strong core of seasoned internationals for that campaign. Along the way, the Reggae Boyz would certainly like to perform well in the games and tournaments it is competing in, but the current squad is more about trying to figure out what a strong Jamaica team will look like in 2019 or 2020 than any serious ambition to make the 2017 Gold Cup final.
Of course, the best way for the incumbent Reggae Boyz to keep their places in the national team is to play well and surprise a few observers. A solid performance against Mexico would get the right sort of attention. This Jamaica team is not expected to come close to matching the achievements of the 2015 Gold Cup squad, but it will certainly try to do so.
Per livesoccertv.com, here's where to find the game if watching from the USA: